There are various settings in which it is necessary or desirable to provide a barrier between a particular working environment and the area surrounding it. Such settings are typically industrial in nature, and a prominent example of such is found on oil and gas drilling facilities, such as offshore platforms, production facilities and the like, in which industrial activities of various sorts regularly occur in close proximity to areas in which the activities would be considered dangerous, or in which the environment in general is not suited to performing certain activities.
In the case of offshore drilling platforms, it is commonly necessary to perform so-called “hot work,” such as welding, cutting, grinding, and the like. Hot work can involve the generation of extremely high temperatures, flames and/or electrical arcs, sparks and fragments of materials being sprayed in uncontrolled directions. It is obviously not advisable or desirable for such activities to be performed in close proximity to hydrocarbon liquids and gases, which for the most part are highly combustible.
In recognition of these concerns, there has been proposed in the prior art the concept of an enclosure intended to surround a working area and isolate the working area from potentially hazardous external conditions in close proximity to the working area. Examples of such enclosures are proposed, for example, in U.S. Pat. No. 7,193,501 to Albarado et al. entitled “Enclosure System Allowing for Hot Work Within the Vicinity of Flammable and Combustible Material;” in related U.S. Pat. No. 7,091,848 to Albarado, entitled “Enclosure System for Hot Work Within the Vicinity of Flammable or Combustible Material;” in U.S. Pat. No. 6,783,054 to Pregeant, Jr. et al., entitled “System for Controllably Conducting Welding Operations Adjacent Flammable Materials and Method of Welding Adjacent Flammable Materials;” and in related U.S. Pat. Nos. 5,101,604 and 5,018,321 to Wardlaw, III, each being entitled “Subterranean Well Welding Habitat.” Each of the foregoing U.S. Patents is hereby incorporated by reference herein in its respective entirety.
While such work area enclosure systems are known, especially in the oil and gas industry, many implementations do not take into account the potential for the activities or conditions inside the enclosure creating hazardous conditions, such as, for example, if an enclosure contained dangerous concentrations of volatile and/or injurious gases and the like. Such conditions are to be carefully avoided to ensure the safety of persons both inside and outside the working area enclosure.
To address these concerns, there have further been proposed in the art various means for ensuring the safety of persons both within and outside of a workspace enclosure. For example, there has been proposed the provision of sensing devices adapted to signal the presence of combustible or otherwise hazardous conditions within the enclosure. The aforementioned Pregeant, Jr. et al. '054 patent (“Pregeant”), for one, appears to disclose a welding enclosure having one or more sensors for detection of some potentially hazardous condition(s), and for controlling the operations of the welding apparatus in response to signals from the sensor(s).
Notwithstanding the apparent safety benefits arising from the Pregeant disclosure and others in the prior art, there are certain perceived disadvantages to the system proposed in the prior art that make such systems and methods less than optimal in certain respects, and it is believed that there remains an ongoing need for improvements in prior workspace enclosures and the control and safety systems associated with those enclosures.